Genetic testing offers an extensive array of new opportunities in evaluating health outcomes, and as a result has captivated the scientific community. This leaves us with questions such as if we should do genetic testing and how this can benefit us.

The basics of genetic testing

Your DNA (or genes) is the foundational blueprint of who you are. Your DNA determines your hair colour, your height, the shape of your ears and even the size of your feet. DNA codes for what you can physically see, as well as what you cannot. Your DNA will also determine how your body processes certain nutrients, how it makes hormones as well as how several metabolic processes take place in your body.

Through the advancements in science, researchers have been able to identify the many sections of DNA and determine their specific functions. Geneticists are able to pin-point sections that influence weight management and certain chronic disease conditions.

Genetic tests are available for the public through labs such as DNAlysis. Labs are able to give unique personalised information about the best way for a specific individual to lose weight, maintain good health and decrease the risk of certain disease conditions. Genetic tests such as these are game changers, as they provide an in-depth view of what alterations are needed for weight loss and health improvements specific to the individual.

For example, although we know heart health depends on a complex balance of environmental, dietary and genetic factors, certain genes influence LDL (bad) and HDL (good) cholesterol levels. If you test strong for the APO E (E3/E4) gene variation your risk for heart disease is increased due to higher levels of LDL cholesterol. This means that you will need to adhere to a healthy lifestyle to reduce your risk of heart disease.

Complex interactions 

You may ask if there is any point in testing ones genes, as we can not change our DNA. Testing your genetics is helpful, as you can determine where you have “loaded guns” or points of concern. A loaded gun is potentially dangerous, but it is only deadly when you “pull the trigger”. Genetics may load the gun but your diet and lifestyle pulls the trigger. If you improve your diet and lifestyle, you will prevent a “gun from triggering” and decrease your risk of getting the disease.

There is no direct relationship between genetics and disease or weight difficulties. For example if you have certain DNA results for the CYP1A1 gene, you may have increased enzyme activity that results in elevated levels of activated metabolites.

This could lead to DNA damage and an increased risk for cancer. Having the CYP1A1 gene does not mean you will definitely develop cancer. Normally a combination of many gene mutations will cause a disease such as cancer, and if you increase your antioxidant intake and decrease your exposure to environmental toxins you may lower your risk for cancer.

Genetic tests can supply a vast amount of information. The following are examples of what genetic tests could indicate:

• If you should eat a Mediterranean or low-fat diet style to lose weight; or how many hours of exercise per week you need for weight control
• What intensity exercise is most effective for you
• How you metabolise certain nutrients
• If you need more of certain nutrients
• Areas where there may be increased risk of diseases or impaired functioning such as bone health, insulin control, detoxifying of waste products by the liver, blood pressure control, cancer risks etc. For example, in the COL1A1 gene there is a problem in the ratio of collagen chains produced by bone cells which leads to reduced bone strength. Individuals with this gene may have an increased risk of bone fracture when calcium is low. Ensuring adequate calcium intake will reduce this risk.

Genetic testing provides a unique insight on health, diet and physical activity optimisation. This does however not mean that conventional intervention is no longer needed, it merely means that it is now more personalised.

Assessments of blood tests, physical examinations, family history, symptoms, eating patterns, stress, sleeping patterns etc. will still provide health professionals with adequate information to guide a patient to become healthier in order to lower disease risks. In other words, it can be seen as another tool in a health professional’s toolbox.

Read more:

Predicting diseases from DNA

DNA barcode library launch

What’s your exercise DNA?

^References:

^{PEN: Practice-based Evidence in Nutrition – Nutrigenomics Background}

^{Phillips CM. Nutrigenetics and Metabolic Disease: Current Status and Implications for Personalised Nutrition. Nutrients. 2013:5; 32-57.}

^{Sales NM, Pelegrini PB, and Goersch MC. Review Article Nutrigenomics: Definitions and Advances of This New Science. Journal of Nutrition and Metabolism. 2014: 1-6.}

Jessica Pieterse